<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge,Chrome=1">
  <meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=no">
  <title>常见问题</title>
   <script type="text/javascript">
        (function (doc, win) {
          var docEl = doc.documentElement,
            resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
            recalc = function () {
              var clientWidth = docEl.clientWidth;
              if (!clientWidth) return;
              docEl.style.fontSize = 20 * (clientWidth / 320) + 'px';
            };
         
          if (!doc.addEventListener) return;
          win.addEventListener(resizeEvt, recalc, false);
          doc.addEventListener('DOMContentLoaded', recalc, false);
        })(document, window);
    </script>
<style>
*{margin: 0;padding: 0;}
div{width: 640px;height: 100px;}
  .con1{
    background: #bbb;
    font-size: 14px;
  }
  .con2{

    background: #1c1c1c;
  }
</style>
</head>
<body id="cjwt">
 <div class="con1">这是测试文字</div>
 <div class="con2"></div>
 <div class="con3"></div>
 


    

 

</body>
</html>